"but it is also really getting load when the fan? is running."
Not sure what you mean by that?
But regardless, it seems from what you have said, there is likely a small leak in the system. The symptoms you talk about do appear to indicate a low gas (refrigerant) situation. It doesn't matter how old the fridge is, most fridges have a leak or two.. It just depends on how bad they are, as to how long the fridge will run before you start to notice problems. Sadly it is likely there is no part you can replace to fix this. If it is a case of a gas leak, you would need special equipment to fix it.
The only easy possibility might be the magnetic door seals. In some older fridges (and new ones), they can sometimes cause problems. I don't think there is an easy way to test them apart from careful inspection. You need to make sure the door/s close firmly and cleanly, without any gaps.
Also take some temperatures (roughly by touch is ok) and compare them with another similar fridge. If you notice a huge difference, it's likely a low gas problem. Another thing, how long does the motor/compressor run for? It should cycle on and off "normally" depending on how often the doors(s) are open and closed. If the compressor runs for hours and never stops, it's likely low gas. Obviously you have checked the thermostat is set lower? Is there an airflow duct between fridge and freezer? That should be open. Is there any ice on the outside of the fridge? If so, means moisture in the lining (insulation) of the fridge.
There are a number of tests you could do, without special equipment.
Firstly, if you are not electrical aware, be careful. You can get killed playing behind and underneath equipment like this.
The fridge is driven by a device called a compressor. That is a sealed metal cylinder or container that takes low pressure cool to cold gas from the fridge, after it has done the job of making you food cold or frozen. There will be a large(er) tube going into the compressor at the back of the fridge (called suction/return). That tube should be cool to cold. There should also be a smaller (hot to very hot) tube (called discharge) connected to the compressor. That's the high pressure gas going to the condenser to be cooled, so it can freeze your food.
If the suction tube into the compressor is not cool to cold, the fridge needs a re-gas or there might be a line blocked. If the small tube or discharge tube is not hot to very hot, you also might have a problem.
Fridges are very hard for non technicians or people without the right equipment, to fix. Nearly impossible. The most common (easy to fix) problems are door seal problems, thermostat problems, airflow problems. Anything to do with the sealed system side is nearly impossible to fix, unless you have the right equipment. It does sound like it's a low gas problem. One last test - is the exit line or exit side (evaporator), inside the fridge (assuming this is a two door fridge) very cold? The evaporator inside the fridge section should be quite cold. The evaporator is the cold plate (usually made of aluminum) that removes heat from your food. The inlet tube will go into one side of that plate and exit to the compressor on the other side. If that's not quite cold, it's another indication of low gas in your system. Maybe have a look at a basic fridge diagram via Google. Might help explain what I'm talking about.
Lastly be safe. Be aware of possible faulty electrical wiring. If you are not aware or trained, playing with the back of fridges can be dangerous. Good luck.